Corynebacterium glutamicum and microorganisms belonging to the genus Corynebacterium have proven to be important in the industrial production of amino acids, including glutamic acid and lysine, and salts thereof including monosodium glutamate. Corynebacterium has, however, proved to be refractory to genetic engineering using recombinant dexoyribonucleic acid (DNA) techniques for lack of suitable Corynebacterium plasmids which can be modified by enzymatic means for use as vectors.
The usefulness of plasmids and modified plasmids as vectors has been repeatedly demonstrated Escherichia coli (E. coli), Bacillus subtillis and Actinomycetes, all of which have been successfully modified using plasmid-derived vectors from each of the respective organisms, to produce chemical substances which are useful. Such substances include antibiotics, enhanced amino acid production and various hormones from eukaryotic, and in particular mammalian, species. The usefulness of Corynebacterium glutamicum, which has been used in numerous large-scale industrial fermentation processes, can be vastly improved if a vector system suitable for use in this microorganism can be developed.